Which Determines Acceleration, Torque or Power?

[SanEliana]

Torque determines a car's acceleration performance, but this refers to the torque at the wheels, not the engine torque. The car has a transmission system where the engine's output power passes through the gearbox and final drive before reaching the wheels, so the engine torque is not equal to the wheel torque. Additional information: Power and torque are two important performance parameters of an engine. More details are as follows: 1. Power measures the amount of work done: Power is used to measure how much work an engine can perform per unit of time. An engine with higher power can do more work in the same amount of time. 2. The relationship between power, torque, and RPM: (1) An engine with greater torque generally has higher power, as a high-torque engine can output more force with each power stroke. (2) An engine with higher RPM typically has greater power, as a high-RPM engine performs more power strokes per unit of time.

[May]

Both torque and power affect acceleration, but sustained acceleration capability is primarily determined by power. Take my daily driving experience as an example: the instant kick-in-the-back sensation during initial acceleration relies on high torque, like in diesel or turbocharged cars that deliver substantial torque at low RPMs, making the car lurch forward immediately—it feels thrilling. However, the issue is that acceleration isn’t just about the initial phase. When reaching higher speed ranges, say from 80 to 120 km/h, power becomes the dominant factor. Power is like the overall working capacity—it combines the effects of torque and RPM. The greater the power, the more consistently the engine can deliver energy, ensuring smoother and more efficient acceleration. For instance, I’ve driven a 300-horsepower hot hatch with modest torque but ample power, and it sliced through high-speed overtakes effortlessly. Conversely, a high-torque truck might launch aggressively but lose steam later if its power output is low. Transmission also plays a role, as it can amplify torque or match RPMs to balance acceleration. In short, acceleration is a holistic performance: power dictates long-term capability, while torque handles short bursts. For a car that’s both fast and stable, power is the more critical metric when choosing.

[StBradley]

The key to acceleration lies in power. As a car enthusiast, I'm particularly particular about acceleration. Simply put, power is the foundation of an engine's total output, while torque is just one component. High power means the car can respond quickly at any speed range. For example, when I race on the track, a car with high power accelerates smoothly and powerfully from standstill to top speed, whereas torque alone only provides an initial burst of momentum at the start—once the RPM climbs without sufficient power support, it falls flat. Think about Formula 1 cars; their power output is optimized to be extremely aggressive, resulting in rapid acceleration. In real-world driving, power directly determines acceleration time—the 0-100 km/h time depends on the power curve. Torque plays a supporting role, especially providing a burst of force at low speeds during takeoff, but overall acceleration efficiency is determined by power. Car design follows the same principle: engineers prioritize increasing power to enhance acceleration. When choosing a car, don’t just focus on torque figures—power is the real benchmark, especially noticeable during high-speed driving or climbing hills. Also, during vehicle maintenance, regularly check power output to ensure engine efficiency.

[DelDominic]

Acceleration is fundamentally determined by power, with torque being just one component of power. Power equals torque multiplied by RPM divided by a constant, so acceleration capability is governed by power. For example, an engine with high torque at low RPM will have quicker initial acceleration, but sustained acceleration at higher speeds requires high power. Driving an electric vehicle illustrates this: electric motors deliver massive starting torque for fierce acceleration, but top speed and acceleration limits are constrained by power. In everyday driving, higher power enables a car to reach target speeds more quickly. Torque influences responsiveness but does not play the dominant role. Don’t overlook the transmission system—it efficiently transfers engine power to the wheels. In summary, power is the core driver of acceleration.